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Shared IP intelligence for Klaviyo senders

You didn't choose your IP neighbors. Klaviyo did.

Nearly every Klaviyo brand sends from shared IPs, so your deliverability is averaged with dozens of companies you have never heard of, and the lineup changes without notice. Nobody shows you who they are. This does: the companies on your addresses, how much of your pool each one holds, and the day Klaviyo quietly moves you.

184 brands · 311 Klaviyo addresses · 20,894 campaigns · Feb 2024 – Jul 2026

Free, and no account. Or open a live pool first: bioma.health · duckcamp.com

ipneighbors / bioma.health

4 other companies draw from the same pool as bioma.health.

Their sending is averaged into the reputation of every address they share, and nobody is told they are there.

  • duckcamp.comsame pool11 shared IPs
    149.72.167.101149.72.197.103149.72.226.45
  • liquid-iv.comsame pool11 shared IPs
    149.72.167.101149.72.197.103149.72.226.45
  • impossibrew.co.uksame pool11 shared IPs
    149.72.167.101149.72.197.103149.72.226.45

Every brand and IP here is real, seen in mail we received

Observed, not claimed

The busiest addresses in the panel.

294 of the 311 Klaviyo addresses we have observed carry more than one company. These are the twelve most crowded. Every name is a brand whose mail we received.

Counts are what the panel has seen between Feb 2024 – Jul 2026, not a claim about an address's full tenancy. We publish adjacency and nothing else — never another brand's performance, volume or placement — and a brand that would rather not appear here comes off the same day.

When you'd use it

Three moments you have already had.

If none of these have happened to you, you do not need this yet.

The checklist came back clean and the client still wants an answer.

Auth aligned, complaint rate under 0.1%, sunset policy running, nothing changed in the creative, and Gmail placement still slid. You have run out of variables you can observe. Pool composition is the one you never could, and it is the only one that moves without you doing anything.

“Should we pay for a dedicated IP?”

Today that answer is judgement. With a roster it is evidence: here is your pool, here is who else is on it, and here is how much of your pool they occupy. It is also the argument you take to Klaviyo when you want to be moved rather than upsold.

You fixed it. Did the platform notice?

You suppressed the dead weight and tightened the segments six weeks ago. Domain reputation in Postmaster is a coarse, lagging band. A change in the IPs you draw from is an early sign the platform re-rated you, and your DMARC reports show it whole.

What we measured

What we measured, not what we assume.

Every figure below came from real campaigns and public DNS. You can reproduce all of it.

3,338
Klaviyo shared IPs mapped, across 2 separate networks
876
Dedicated IPs, resolving to 287 named brands
20,894
Klaviyo campaigns observed, from 184 brands
58
Brands sharing one single address
reproducible — dig, whois, and a for-loop
$ dig +short -x 167.89.100.92
o1308.shared.klaviyomail.com.        ← FCrDNS confirms a shared node

$ dig +short TXT klaviyomail.com
"v=spf1 include:sendgrid.net ~all"   ← the SendGrid half

$ whois 170.203.24.13 | grep OrgName
OrgName:   Klaviyo, Inc              ← a second network, their own /20

$ dig +short -x 170.203.25.10
kl-203-25-10.k3.mail.horze.com.      ← dedicated IPs name the customer

Klaviyo runs on SendGrid, and SendGrid documents the mechanism themselves: “if there is a sender in your pool that starts to underperform, within a day they will be automatically transitioned to a different pool.” Sorted by engagement quality, not just complaints. Nobody is notified in either direction.

How it works

Three steps. Only the first needs you.

  1. 1

    Append one address to your DMARC record

    Comma-separated onto your existing rua=. Nothing about your sending changes and no subscriber sees anything.

    10 minutes · no code · non-disruptive

  2. 2

    Receivers report the IPs

    Gmail, Yahoo, Microsoft and the long tail already report every source IP that sent as your domain, with volumes. Adding our address puts us on the same report.

    complete, not sampled · daily

  3. 3

    We tell you when the pool moves

    Not when an IP changes, which is constant and meaningless. When the set behind it changes, with the sends that preceded it.

    silence means nothing moved

The category

Why no other tool shows you this.

Not because it is hard to build. We checked the category. It is who they sell to.

  • Validity could ship this tomorrow

    They run the largest email panel in the industry, and Everest already sells competitive intelligence on what rival brands send. It does not publish co-tenancy. They also sell reputation and certification services to the ESPs whose pools this would expose, at $1,000–2,000 a month. That is a conflict of interest, not a technical gap.

  • Placement testers answer a different question

    GlockApps and the seed-list tools tell you where your mail landed. A placement test only ever observes one sender, so it structurally cannot see who else was on the address that carried you. That needs a panel receiving many brands at once.

  • The DMARC platforms stop one step short

    dmarcian, EasyDMARC, Valimail and Postmark's free digest parse the same reports and list every IP that sent as your domain. None cross-references those addresses against other senders, because none of them holds other brands' received mail.

  • Klaviyo has no reason to

    Asked on their own forum why a customer's pool had changed, Klaviyo's answer was “I believe that we have IP pools run on an automatic basis.”

    Source: Klaviyo Community, “Changed IP pool”

Limits

What it isn't.

You have been pitched by every vendor in this category. Here is the part they leave out.

The offer

The infrastructure answer, in writing.

Not a dashboard to check. One document that tells you whether your sending infrastructure changed, so you can stop guessing and go fix the right thing.

Pool audit

£2,500one-off, delivered inside a week
  • Every address that carried your mail, complete from your own DMARC reports rather than sampled. Typically ten to thirty; Klaviyo shows you none of them.
  • Every other company we have observed on those addresses, named, with how much of your pool each one occupies.
  • The dates Klaviyo moved you, if it did, and the campaigns that went out in the fortnight before each move.
  • A written verdict you can put in front of your CMO, and a support ticket you can send Klaviyo with a date on it.
Read the sample reportPrice & how ordering works

The sample is the exact document, built on a real sender from the panel. Ordering is one email and one DNS record; the report arrives inside a week.

What it will not tell you
Whether your neighbours’ inbox placement moved when yours did. That question needs several senders in the same pool reporting at once, and today we do not have them. When we can answer it we will, and until then we would rather write this than guess. It also cannot move you: Klaviyo requires roughly a million marketing emails a month plus an enterprise plan before a dedicated IP is on the table, so for almost everyone the pool is not a choice. What changes is that you stop paying for the wrong fix.
Who this is for
Klaviyo senders past roughly 300,000 emails a month, where a fortnight spent re-segmenting the wrong thing costs more than the audit does. Below that, use the free lookup and keep your money.
Why we can publish this
We sell nothing to Klaviyo, SendGrid or any ESP, and take no certification or reputation money from them. That is the only reason this exists and the incumbents' does not.
On naming names
We name who shares your pool, because that is observable fact. We never publish another brand’s performance, volume or placement, and a brand that asks to come off comes off the same day.